This invention relates generally to article handling apparatus and more specifically to an apparatus for rapidly removing molded articles from plastic molding machines, as well as articles formed by various other manufacturing processes. A number of systems are known in the prior art for removing molded articles following ejection of those parts from a conventional injection molding machine, for example. Included are simple systems in which molded articles are permitted to drop from the mold after ejection, labor intensive manual systems, conveyor systems that transport the articles after they have been ejected, and more complex mechanical grasping and suction systems that serve to remove the ejected articles. The prior art manual systems result in contamination of dropped articles and the need for additional subsequent handling. The prior art mechanical grasping and suction systems are disadvantageous in that most of them suffer from slow operating speeds. In today's manufacturing processes, it is increasingly important to maximize the output of manufactured articles to control the cost of production and thereby maintain a competitive position in the marketplace. This need for high output is particularly important in the plastic molding industry, for example, where molding cycles may be no more than a few seconds. The production rate in this industry has been limited by the inability of prior art article handling devices to rapidly retrieve molded parts from a mold so that a new molding cycle may begin.
It is therefore a principal object of the present invention to provide a retrieval system for rapidly removing articles from a plastic molding machine or other manufacturing process to significantly shorten the manufacturing cycle time over prior art manufacturing processes that employ automated article retrieval systems. The speed advantage afforded by the present invention is achieved by realizing acceleration rates on the order of 26 G's as compared to acceleration rates in prior art article retrieval systems of 6-10 G's.
This and other objects are accomplished in accordance with the illustrated preferred embodiment of the present invention by providing two pairs of lightweight non-metallic telescoping retrieval tubes arranged for telescoping motion into and out of an open mold. Each pair of telescoping retrieval tubes is coupled to a pair of telescoping bearing tubes. The retrieval and bearing tubes are driven in concert by a low inertia cable drive system. Each of the telescoping pairs of retrieval and bearing tubes includes strips of plastic bearing material.